Perhaps you should try some spelling variations:
sach tranh » canh tranh
sach hanh » sach danh, sac hanh, cach nhanh
thuat do » thuat o
sach han » sach tham, sach danh, sach nang
tu sach » thu sach, su sach, te sach
tranh y » trinh y, tranh o, tranh 30
y thuat » my thuat, kxy thuat, ki thuat
do hoa » dong hoa
toan » tran

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach tranh y thuat do hoa ) or ( so ((sach hanh) OR (sach han)) ky thuat toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tranh y thuat do hoa ) OR ( so ((sach hanh) OR (sach han)) ky thuat toan khoa )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach tranh y thuat do hoa ) or ( so ((sach hanh) OR (sach han)) ky thuat toan khoa ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach tranh y thuat do hoa ) or ( so ((sach hanh) OR (sach han)) ky thuat toan khoa ))*.